Sputtering apparatus

ABSTRACT

A magnetron assembly for a rotary target cathode comprises an elongated support structure, a magnet bar structure movably positioned below the support structure, and a plurality of drive modules coupled to the support structure. The drive modules each include a motorized actuation mechanism operatively coupled to the magnet bar structure. A controller and battery module is coupled to the support structure and is in operative communication with the drive modules. The controller and battery module includes an electronic controller and at least one rechargeable battery. The battery is configured to energize each motorized actuation mechanism and the electronic controller. One or more power generation modules is coupled to the support structure and in electrical communication with the battery, such that electrical energy output from the power generation modules recharges the battery.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/263,250, filed on Apr. 28, 2014, which is a continuation-in-part ofU.S. patent application Ser. No. 14/019,877, filed on Sep. 6, 2013,which claims the benefit of U.S. Provisional Patent Application Ser. No.61/771,460, filed on Mar. 1, 2013, all of which are incorporated hereinby reference.

BACKGROUND

Magnetron sputtering of rotating targets is well known and is usedextensively for producing a wide variety of thin films on a wide varietyof substrates. In the most basic form of rotating-target magnetronsputtering, the material to be sputtered is either formed in the shapeof a tube or is adhered to the outer surface of a support tube made of arigid material. A magnetron assembly is disposed within the tube andsupplies magnetic flux, which permeates the target such that there isadequate magnetic flux at the outer surface of the target. The magneticfield produced by the magnetron assembly is designed in a way such thatit retains electrons emitted from the target so as to increase theprobability that they will have ionizing collisions with the workinggas, hence enhancing the efficiency of the sputtering process.

It is becoming increasingly important to compensate for target erosioneffects because it is desirable to increase target thickness and operatesputter processes under more sensitive process conditions. The desirefor thicker targets is largely driven by fabrication costs of ceramictargets, but is also desirable in order to have a greater inventory ofusable material inside the sputter coater in order to run longer coatingcampaigns. The need to run processes in more sensitive processconditions is driven by the desire to get higher deposition rates, inreactive mode sputtering, and/or to finely control film chemistry.

Fabrication cost for targets of some materials, in particular ceramictransparent conductive oxide (TCO) materials, are relatively high incomparison to the cost of the raw materials. To improve the economy ofthese targets, it is desirable to increase the thickness of the targetmaterial. In this way, the target will have significantly more usablematerial while adding only minimally to the overall cost of the target,as the fabrication cost does not change significantly. The onlysignificant cost increase is due to the additional raw material used. Inaddition, thicker targets have the added benefit of allowing longerproduction campaigns between target changes.

Increasing the target thickness too much, however, can result ininadequate magnetic flux at the target surface when using standardmagnetron assemblies. Magnetron designs with higher magnetic flux haverecently been introduced to provide the higher magnetic flux requiredfor the thicker targets.

In the case of reactive magnetron sputtering, metallic targets aresputtered in an atmosphere that contains reactive gas such as oxygen ornitrogen. The sputtered material reacts with the reactive gas in orderto form a film comprised of compounds of the target material and thereactive gas. The reactive gas also reacts with the target surface,thereby forming reacted compounds on the target surface. The surfacecompounds greatly reduce the ablation rate. In order to improve thesputtering efficiency, the amount of reactive gas may be carefullycontrolled so as to minimize the target surface reactions while stillachieving the desired film chemistry. In some cases, the processes needto be controlled such that the chemistry of the film issub-stoichiometric.

This fine control over the process gas makes the process sensitive tosmall perturbations. The industry has seen considerable technologicaladvances in power delivery and process gas control that have minimizedmany of the process perturbations. Nevertheless, little has been done tominimize variations in the magnetic confinement of the plasma. As thetarget erodes, the working surface gets closer to the magnetic assemblyand the magnetic field becomes stronger. This changes the confinement ofthe plasma, altering the dynamics of the sputtering process. Thispresents a challenge in maintaining long-term stability of the process.

The typical magnetron assembly for rotating cathodes comprises threesubstantially parallel rows of magnets attached to a yoke ofmagnetically conductive material, such as steel, that helps complete themagnetic circuit. The direction of magnetization of the magnets isradial with respect to the major axis of the sputtering target. Thecenter row of magnets has the opposite polarity of the two outer rows ofmagnets.

Magnetic flux of the inner and outer rows of magnets is linked throughthe magnetically conductive yoke, on one side of the magnets. On theother side of the magnets, opposite the yoke, the magnetic flux is notcontained in a magnetically conductive material. Hence, the magneticflux permeates substantially unimpeded through the target, which issubstantially non-magnetic. Thus, two arc-shaped magnetic fields areprovided at and proximate to the working surface of the target. Thesefields retain the electrons and cause them to drift in a directionperpendicular to the magnetic field lines, which is parallel to the rowsof magnets. This is known as the ExB drift. In an ordinary arrangement,this drift path is also parallel to the major axis of the target.

Additionally, the outer rows of magnets are slightly longer that theinner row of magnets, and additional magnets, of the same polarity asthe outer rows, are placed at the ends of the assembly between the twoouter rows creating the so-called “turn-around” areas of the drift path.This has the effect of connecting the two drift paths, hence forming onecontinuous ovular “racetrack” drift path. This optimizes the retentionof the electrons and therefore optimizes the efficiency of thesputtering process.

As the target erodes, the working surface comes closer to the magnetassembly, and the intensity of the magnetic field, at the workingsurface, increases in a non-linear fashion. For finely controlledprocesses it very desirable to modify the magnetic field, as the targeterodes, so as to minimize variability of the process, thereby making theprocess easier to control over the course of the target life.

The need for changing the magnetic field as the target erodes is wellknown, and has been accomplished in the case of planar sputteringcathodes. The need for an adjustable magnetron for rotating cathodes hasgone unsatisfied, however, because the geometry and mechanical structureof the cathodes make the task especially challenging.

International Publication WO 2013/120920 (the '920 publication)discloses an end-block for rotatably carrying a sputter target tube andrestraining an adjustable magnet bar inside the target tube. Connectorsare employed inside the end-block for power and communication feeds. Useof these connectors would require significant redesign of a typicalend-block, making retro-fitting of older cathodes infeasible with suchconnectors.

SUMMARY

A magnetron assembly for a rotary target cathode comprises an elongatedsupport structure, a magnet bar structure movably positioned below thesupport structure, and a plurality of drive modules coupled to thesupport structure. The drive modules each include a motorized actuationmechanism operatively coupled to the magnet bar structure. A controllerand battery module is coupled to the support structure and is inoperative communication with the drive modules. The controller andbattery module includes an electronic controller and at least onerechargeable battery. The battery is configured to energize eachmotorized actuation mechanism and the electronic controller. One or morepower generation modules is coupled to the support structure and inelectrical communication with the battery, such that electrical energyoutput from the power generation modules recharges the battery.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a magnetron assembly for a rotatabletarget cathode according to one embodiment;

FIG. 2 is an end view of the magnetron assembly of FIG. 1;

FIG. 3 is a side view of the magnetron assembly of FIG. 1;

FIG. 4 is a cross-sectional side view of the magnetron assembly takenalong line 4-4 of FIG. 2;

FIG. 5 is an enlarged sectional view of the magnetron assembly takenalong line 5-5 of FIG. 4;

FIG. 6 is a cross-sectional end view of the magnetron assembly takenalong line 6-6 of FIG. 3;

FIG. 7 is a cross-sectional side view of a magnetron assembly in arotatable target cathode according to another embodiment;

FIG. 8 is an enlarged sectional view of the magnetron assembly takenalong line 8-8 of FIG. 7;

FIG. 9 is a partial cross-sectional side view of a sputtering apparatusaccording to one embodiment;

FIG. 10 is a schematic illustration of a sputtering apparatus accordingto another embodiment;

FIG. 11 is a perspective view of a magnetron assembly for a rotarytarget cathode according to another embodiment;

FIG. 12 is a top view of the magnetron assembly of FIG. 11, with some ofthe components removed to show internal structures;

FIG. 13 is an end view of a rotary target cathode according oneembodiment that contains the magnetron assembly of FIG. 11;

FIG. 14 is a cross-sectional side view of the rotary target cathodetaken along line 14-14 in FIG. 13;

FIG. 15 is an enlarged sectional view of an end portion of the rotarytarget cathode taken along line 15-15 in FIG. 14;

FIG. 16 is an end view of a rotary target cathode according anotherembodiment that contains the magnetron assembly of FIG. 11;

FIG. 17 is a cross-sectional side view of the rotary target cathodetaken along line 17-17 in FIG. 16; and

FIG. 18 is an enlarged sectional view of an end portion of the rotarytarget cathode taken along line 18-18 in FIG. 17.

DETAILED DESCRIPTION

An apparatus and technique for rotating-cathode magnetron sputtering isprovided that deals with the variation in magnetic intensity at thesputtering surface as a target erodes, which results in changing processconditions. By magnetically compensating for target erosion effects, thepresent approach improves process stability.

In some embodiments, can adjustments in the position of a magnetronassembly be made by pneumatic or hydraulic pressure that pushes againsta spring loaded mechanical structure. The spring can push the magnetronassembly either towards the nearest or towards the furthest distancefrom the target's working surface while the pneumatic or hydraulicpressure pushes against the spring, in the opposite direction. Theapplied pressure will determine the position of the assembly. In suchembodiments, the pressure-carrying line can be disposed within a centralwater tube, on which the magnetron assembly is generally mounted. Thislocation is beneficial because the water tube remains static. Thus, noseals are required on moving parts and reliability is optimized.

In one embodiment, energy is provided to a pneumatic actuator through apressurized gas cylinder disposed within the target assembly. Thehigh-pressure gas cylinder can be a commercially available carbondioxide (CO₂) cartridge, for example.

In other embodiments, the motion for making adjustments can be providedby a cable, which also can be disposed within the water tube. In oneexample, the cable can be rotary, such as in a speedometer of a car. Inanother example, the cable can be push/pull, such as in a hand-brakecable on a bicycle.

Depending on the specific design of the cathode being used, someembodiments of the present approach can provide motion directly by wayof a rotary or linear shaft that is disposed within the water tube alongthe axis of the target assembly. The shaft passes from air to waterthrough an air-to-water seal, such as a rotary seal. In the case oflinear motion, the motion can be transmitted via a bellows, whichprovides complete air-to-water isolation and transfers motion throughcompression or expansion of the bellows.

In some cathode designs, one end of the target assembly is attached toan end-block through which all functions pass, and the other end of thetarget is capped. This type of cathode is referred to as a single-endedcathode. The capped end may or may not be supported by a bearing. Inthis type of cathode design, the above mentioned bellows can be part ofthe end-cap design.

Another method of providing a mechanical feed-through is magnetically. Amagnetic assembly inside the target structure can magnetically couple toan assembly outside the target. The motion of the external assembly willtranslate, via the magnetic link, through a solid wall. Such anarrangement can most easily be implemented as part of the end-cap of asingle-ended cathode design.

In other embodiments, adjustments can be driven by taking advantage ofthe motion of the target rotation relative to the staticmagnetron/water-tube assembly. This can be done by providing amechanical structure, such as gears, to harness the rotary motion of thetarget to drive the actuators used to make the adjustment. In anotherembodiment, adjustments can be driven by harnessing the water flowthrough the cathode, as by a turbine or water-wheel mechanism, such aswhen the water flows through the central water tube. In such cases asthe target rotation or water flow driven embodiments, it is necessary toprovide a structure for engaging and dis-engaging the mechanism fromoutside the coater, such as a switching mechanism, which can use any ofthe mechanical feed-through methods previously discussed.

In further embodiments, adjustments can be made by internal motors suchas servos or stepper motors contained within the target assembly, whichcan be either submergible or contained inside a water-tight housing.These motors can apply torque directly to an adjustment screw, or therecan be intermediate mechanics. The intermediate mechanics can be wormgears, bevel gears, or rack and pinions, for example, which change thedirection of motion. Such mechanics can also serve as gear reductions inorder to adjust the relative torque between the output torque of themotor and the desired torque to be applied to the adjustment screw.

In an alternative approach, piezo-electric motors can be utilized in theactuation mechanism. The piezo-electric motor provides a linear motion.This motion can be translated to rotary motion, to drive an adjustmentscrew, by applying tangential force to a gear that is affixed to theadjustment screw. Other linear motion options include electricsolenoids, and pneumatic or hydraulic cylinders.

While power for internal motors can be provided by wires that are runthrough the water tube assembly, difficulties can arise in shieldingthese wires from the electrical power applied to the cathode, andbecause of the extra connection required when assembling the target.Alternately, power can be routed in by brush contacts, especially on acapped end of a single-ended cathode.

Another method of driving internal motors is by providing battery packswithin the target cavity. In this approach, power can be switched on andoff by any of the mechanisms previously discussed. As battery packs holda finite amount of energy, the number of adjustments during a productioncampaign can be limited. In most cases, battery life will be sufficientsince the number of adjustments required will be few. In order toaugment the system power, one or more optional power generator modules,such electrical generators, can be added to the magnetron assembly.Output power, from the generator modules, can be used to keep thebatteries charged or used to directly drive the motors of the magnetronassembly. Mechanical energy, needed to drive the generator modules, canbe harnessed from the flow of the cooling water, or by the rotationalenergy of the target cylinder relative to the magnetron assembly. Forexample, small turbine generators that run off the water flow can beimplemented in the generator modules in one embodiment.

In general, pneumatic embodiments of the actuator require less powerthan motorized embodiments.

In another embodiment, an electronic internal control module can belocated within the target assembly. Command and feedback communicationsbetween the operator and the internal control module can be done by avariety of methods that do not require significant alteration of thecathode.

One method for remote communicating with the internal control module isby a power-line overlay signal. In this case, the communications signalis transmitted through the same conductance path as the power applied tothe target. However, communications frequencies must be chosen to bevery different from any power frequency of the sputtering power supply.Additionally, it may be necessary to send redundant signals tocompensate for electrical noise that is occasionally generated by thesputtering process. This method of communication has the advantages ofbeing easily implemented in most rotary cathode designs with virtuallyno modifications to the cathode structure and requires no specialfeed-through.

Alternate methods of communicating with the control module includetransmitting signals through a window in the cathode or target assembly.The most convenient place for such a window is as the center of the endcap of the single-ended type cathode. In this way, it is not necessaryto adapt the end-block to comprise connectors, as with the '920publication. It is not even necessary to provide a connector. Rather, inthe present configuration of the windowed end cap, it is only necessarythat optical fibers, on either side of the window, are in sufficientproximity and alignment to effectively communicate, and are sufficientlyshielded from the plasma to prevent signal noise.

Exemplary types of signals that can be sent through this window includeradio, Wi-Fi, Bluetooth, optical, magnetic induction, or the like.Digital optical communications have the advantage of being immune tointerference from electromagnetic noise produced by the sputteringprocess, but the communication path needs reasonable shielding fromlight. Radio and Wi-Fi signals need shielding from electro-magneticnoise. Magnetic induction communication involve two inductive coils inclose proximity, where a first coil is activated by an electric currentand a second coil acts as a pick-up coil that generates a voltage signalin response to the magnetic field produced by the first coil. All ofthese methods can provide two-way communications. A variation of themagnetic induction method is to replace one of the coils with a Hallsensor, but this limits communications to one-way.

Another alternative for remote communication is by use of a pair ofultrasonic transceivers. Ultrasonic communication has the advantage inthat there is more versatility in where the transceivers are mounted,since they do not require line-of-sight or any special window throughwhich to transmit. Additionally, ultrasonic transceivers do not sufferfrom any electro-magnetic noise, optical noise, or optical impedance.The advantages of ultrasonic communication make it easier to retrofitcathodes produced by a variety of manufacturers.

A method of sensing the position of the magnet assembly, relative thetarget working surface, is also provided. In one approach, directmeasurement is performed using an analog or digital linear motionindicator. If the motion is driven by servos or stepper motors, afeedback signal is available from these motors. An alternate method forsensing position is to measure gas pressure inside the pneumaticelements. Another method is to have a magnet and a Hall probe mounted inthe apparatus such that they move relative to one another as adjustmentsare made. The Hall probe will have a different voltage output dependingon its distance from the magnet.

The various techniques disclosed herein can be used to position theentire magnet assembly as a single unit, or to position multiple pointsalong the length of the magnet assembly, independently, so as to make itpossible to also adjust uniformity of the process.

FIGS. 1-3 and 6 illustrate various views of a magnetron assembly 100 fora rotatable target cylinder according to one embodiment. In general,magnetron assembly 100 includes a rigid support structure 102 such as acoolant tube, a magnet bar structure 104 movably attached to supportstructure 102, and one or more actuation mechanisms 108 coupled tosupport structure 102. The actuation mechanisms 108 are configured tochange a distance of magnet bar structure 104 from a surface of therotatable target cylinder.

The actuation mechanisms 108 are covered by an actuator housing 109. Aposition indicating mechanism is located in actuator housing 109 and isoperative to measure the position of magnet bar structure 104 relativeto the surface of the rotatable target cylinder. The magnet barstructure 104 includes an array of substantially parallel rows ofmagnets 110 attached to a yoke 112, as shown in FIG. 6. The yoke 112 iscomprised of a magnetically conductive material such as steel, whichhelps to complete a magnetic circuit.

A control housing 106 partially surrounds support structure 102 andcontains a communications device configured to receive command signalsfrom outside of magnetron assembly 100 and transmit information signalsto outside of magnetron assembly 100. The control housing 106 alsoencloses an electronic controller in operative communication withactuation mechanisms 108. The communications device can be a transceiverthat is operatively coupled to the electronic controller. Thetransceiver can be a radio frequency (RF) transceiver, an opticaltransceiver, or an ultrasonic transceiver, for example. As shown in FIG.1, control housing 106 defines a position feedback connection port 114and one or more actuation connection ports 116.

The position indicating mechanism can be implemented as a built-inposition sensor in each actuation mechanism 108. The position sensor canmeasure the position of magnet bar structure 104 either by directsensing or by an indirect metric. For example, the position indicatingmechanism can be implemented with a Hall probe and a magnet in an analogsensor. Alternatively, the position indicating mechanism can beimplemented with a digital indicator, such as a plunger style digitalindicator, which transmits data directly to an operator withoutadditional processing.

In addition, a power source can be provided to energize actuatormechanisms 108 and the electronic controller. The power source can befully self-contained within the volume of the magnetron assembly. Forexample, a power supply such as a battery pack can be located in controlhousing 106.

The actuation mechanisms 108 can be implemented in various ways. Forexample, the actuation mechanisms 108 can include a spring-loadedpneumatic structure or a spring loaded hydraulic structure.Alternatively, the actuation mechanisms 108 can include a rotary cableor a push/pull cable.

In one embodiment, each actuation mechanism 108 can include aspring-loaded pneumatic bellows, bladders, or cylinders. In thisapproach, adjustment points are spring loaded with the pressure in thepneumatic element pushing in the opposite direction. Reserve energy formaking adjustments can be stored in a compressed gas supply such as aCO₂ gas cartridge. Adjustments can be made by adjustment valves thateither release compressed gas from the CO₂ gas cartridge into thepneumatic elements, or release gas from the pneumatic elements intocooling water inside the target.

Further details of one embodiment of actuation mechanisms 108 withbuilt-in position sensing are depicted in FIGS. 4 and 5. In thisembodiment, the actuation mechanisms 108 include a sensor port 120 for aHall probe, a pneumatic actuation port 122 configured to receive acompressed gas, and a bellows 124 such as a welded bellows incommunication with pneumatic actuation port 122. A control shaft 130 iscoupled to bellows 124 and yolk 112 of magnet bar structure 104. Areturn spring 128 is coupled to control shaft 130, and a magnet 126 islocated in control shaft 130 for Hall probe feedback. The Hallprobe/magnet in this embodiment is an analog detector for positionsensing. FIG. 6 illustrates exemplary locations within control housing106 for a control board 113 for the controller, one or more solenoidvalves 115, transceivers 117, a CO₂ gas cartridge 118 in fluidcommunication with the solenoid valves, and a battery 119 to run thecontrol board, which are used with the actuation mechanisms 108 of FIGS.4 and 5.

As discussed previously, the actuation mechanisms can alternatively beimplemented with a motorized structure, such as a servo, a steppermotor, or a piezo-electric motor. Any number of mechanicalconfigurations can be used for the drive motion. One example is a screwjack, which may additionally incorporate right-angle gears or reductiongears. In these embodiments, position sensing of the magnet bar can becarried out through feedback from the motorized structures.

FIGS. 7 and 8 illustrate a magnetron assembly 140 implemented with amotorized structure in a rotatable target cathode 170 according to oneembodiment. In general, magnetron assembly 140 is disposed inside of atarget cylinder 172 and includes a rigid support structure 142, a magnetbar structure 144 movably attached to support structure 142, and aplurality of motorized actuation mechanisms 146 coupled to supportstructure 142. The motorized actuation mechanisms 146 include gearedstepper motors 148, which can have a 100:1 gear reduction, for example.A set of bevel gears 150 is operatively coupled to stepper motors 148.The bevel gears 150 can have a 4:1 gear reduction, for example. Athreaded housing 152 is mated with each of bevel gears 150. A threadedpost 154 is coupled between magnet bar structure 144 and threadedhousing 152. An actuator housing 155 encloses each of motorizedactuation mechanisms 146.

The magnetron assembly 140 also includes an electronic controller 156 inoperative communication with motorized actuation mechanisms 146. Acommunications device such as an ultrasonic transceiver/transducer 158is operatively coupled to electronic controller 156. Power for steppermotors 148 and electronic controller 156 can be provided by a batterypack 160. A control housing 162 encloses electronic controller 156 andbattery pack 160.

The target cylinder 172 is rotatably attached to an end block 174 asshown in FIG. 7. An ultrasonic transceiver/transducer 176 is mounted onend block 174 and is in communication with ultrasonictransceiver/transducer 158.

FIG. 9 illustrates a sputtering apparatus 200 according to anotherembodiment that is configured for two-way optical communications. Arotatable cathode target cylinder 210 is disposed within a vacuumchamber 212 having an outer wall 215. The target cylinder 210 isoperatively coupled to a motor 213 mounted on outer wall 215 outside ofvacuum chamber 212. A magnetron assembly 100, such as describedpreviously with respect to FIGS. 1-3, is located within target cylinder210.

As depicted in FIG. 9, an optical communications box 214 is locatedoutside of vacuum chamber 212 on outer wall 215. A first fiber opticcable 216 in atmosphere is optically coupled to a first opticaltransceiver in optical communications box 214. The fiber optic cable 216is also coupled to a vacuum coupler 218, which provides a feedthroughfrom atmosphere to vacuum for fiber optic cable 216. A second fiberoptic cable 224 is coupled to a second optical transceiver insidecontrol housing 106 through a cathode water cooling circuit of targetcylinder 210. A fiber optic window 220 in an end cap 222 of targetcylinder 210 allows an optical signal to be transmitted between fiberoptic cable 216 and fiber optic cable 224.

FIG. 10 is a schematic illustration of a sputtering apparatus 300according to another embodiment, which is configured for two-wayultrasonic communications between a magnetron assembly 310, locatedwithin a rotary cathode assembly 320 in a vacuum chamber 340, and anexternal controller 344 outside of vacuum chamber 340. The magnetronassembly 310 includes a magnet bar structure 312, and a plurality ofmotorized actuation mechanisms 314 mechanically coupled magnet barstructure 312. An internal electronic controller 316 is in operativecommunication with motorized actuation mechanisms 314, such as throughmotor control cables 318 that can include two sets of twisted pairs. Abattery pack housed with electronic controller 316 provides power tomotorized actuation mechanisms 314 and electronic controller 316.

The rotary cathode assembly 320 includes a target cylinder 322, whichcan be filled with water, rotatably coupled to an end block 324. A firstultrasonic transceiver 326 is mounted inside of target cylinder 322 andis in signal communication with electronic controller 316, such asthrough an ultrasonic communication wire 328 that can include onetwisted pair. A second ultrasonic transceiver 330 is mounted on endblock 324 over an insulator 332 and is in ultrasonic communication withultrasonic transceiver 326. The external controller 344, which can beoperated by a user, is in signal communication with ultrasonictransceiver 330, such as through an ultrasonic communication wire 334that passes through a vacuum coupler 336, which provides a feedthroughfrom atmosphere to vacuum chamber 340.

In one implementation, electronic controller 316 is capable ofcontrolling up to twelve (12) axes of motion for magnet bar structure312, with only one motor of a motorized actuation mechanism 314 beingcontrolled at any one time. The control theory for electronic controller316 can be adapted to move each motor a small amount in a givensequence. Controlling only one motor at a time simplifies the controlsystem and reduces the battery requirements as there is a lowerinstantaneous power draw. In addition, the control lines can be routedwith a communications bus on the magnet bar side of an I-beam support. Awater sealed electrical connection can be used between each controlledunit and the communications bus.

In another embodiment, a system for two-way transmission of informationbetween a magnetron assembly contained within a cathode target assemblyand outside of a vacuum chamber can also be provided. For example,two-way communications can be carried out by two RF transceiversstrategically placed, with one transceiver inside the target assemblyand one transceiver outside the target assembly but inside the vacuumchamber. The transceiver inside the target assembly is directlyconnected to the electronic controller. The transceiver in the vacuumchamber is connected to the outside via an electrical feed-through inthe chamber wall. It is necessary to provide a window betweentransceiver antennas that is transparent to the communication signal.The window can be located as part of the end cap of the single-endedcathode.

FIGS. 11 and 12 illustrate a magnetron assembly 400 for a rotary targetcathode according to another embodiment. The magnetron assembly 400generally includes a plurality of drive modules 410, and a plurality ofpower generation modules 414 located along the length of magnetronassembly 400. The magnetron assembly 410 also includes a controller andbattery module 418 in operative communication with drive modules 410 andpower generation modules 414. The drive modules 410, power generationmodules 414, and controller and battery module 418, are each positionedbetween a pair of opposing side walls 422, 424 that extend along thelength of magnetron assembly 400.

As shown in the exemplary embodiment of FIG. 11, a first drive module410-1 and a second drive module 410-2 are located on opposite sides of afirst power generation module 414-1. A third drive module 410-3 and afourth drive module 410-4 are located on opposite sides of a secondpower generation module 414-2, which can act as a redundant powergeneration source in case power generation module 410-1 fails. Thecontroller and battery module 418 is located in a central portion ofmagnetron assembly 400 between drive module 410-2 and drive module410-3.

FIG. 12 is a top view of magnetron assembly 400, with the drive modulesremoved. An elongated support structure 420, such as an I-beam, extendsalong the bottom of magnetron assembly 400 between side walls 422 and424. A plurality of apertures 421 in support structure 420 allows thedrive modules to be coupled to support structure 420 with standardfasteners. The power generation modules 414-1, 414-2, and the controllerand battery module 418, can be coupled to support structure 420 is asimilar manner.

A magnet bar structure 425 with an array of magnets (FIG. 11) is movablypositioned along the bottom of magnetron assembly 400 below supportstructure 420. The drive modules 410 each include a motorized actuationmechanism operatively coupled to magnet bar structure 425 to provideadjustments in the position of magnet bar structure 425. The controllerand battery module 418 includes an electronic controller and at leastone rechargeable battery.

The power generation modules 414 are in electrical communication withthe rechargeable battery such that electrical energy output from powergeneration modules 414 can charge the battery when needed. Electricalpower from the battery is configured to energize the motorized actuationmechanisms and the electronic controller. Alternatively, the powergeneration modules can be configured to directly drive the motorizedactuation mechanisms.

As depicted in FIG. 12, a first water inlet/outlet structure 426 at oneend of magnetron assembly 400 extends through a first end structure 428and is in fluid communication with a pair of cooling pipes 430, 432. Asecond water inlet/outlet structure 434 at an opposite end of magnetronassembly 400 extends through a second end structure 436 and is also influid communication with cooling pipes 430, 432. In one embodiment, afiber optic holder 437 extends through water inlet/outlet structure 434.The fiber optic holder 437 is configured to support a fiber optic cable,which is coupled to an optical transceiver in communication with theelectronic controller.

A set of target cylinder rollers 446 can be located on side walls 422and 424. The rollers 446 provide movable surfaces that allow a targetcylinder to more easily rotate around magnetron assembly 440.

In one embodiment, mechanical energy needed to drive power generationmodules 414, can be harnessed from the flow of the cooling water throughcooling pipe 430 or cooling pipe 432. For example, power generationmodules 414 can include small turbine generators that are in fluidcommunication with water flowing through one or more of the coolingpipes. In an alternative embodiment, the mechanical energy needed todrive power generation modules 414 can be harnessed from the rotationalenergy of a target cylinder surrounding magnetron assembly 400.

FIGS. 13 and 14 illustrate a rotary target cathode 500 that isimplemented with magnetron assembly 400 according to one embodiment. Thecathode 500 includes a rotatable target cylinder 510 having an innersurface 511 that defines an interior passageway. The magnetron assembly400 is disposed in the interior passageway of target cylinder 510. Thetarget cylinder 510 is configured at a proximal end 512 for mounting toan end block of a sputtering apparatus, such as end block 174 (FIG. 7).A target end cap 514 is affixed to a distal end 516 of target cylinder510.

A fiber optic support 520 is configured to be mounted to a vacuumchamber wall of the sputtering apparatus, such as wall 215 (FIG. 9),with fiber optic support 520 being adjacent to but spaced apart from endcap 514. The end cap 514 and fiber optic support 520 are described infurther detail with reference to FIG. 15 hereafter.

FIG. 14 shows further details of magnetron assembly 400. Each of drivemodules 410 includes a motor 530 such as a stepper motor operativelycoupled to an actuation mechanism 534. A set of actuation posts 538 iscoupled between magnet bar structure 425 and each actuation mechanism534. The motorized actuation mechanisms 534 provide for adjustments inthe position of magnet bar structure 425 relative to inner surface 511of target cylinder 510. For example, when target cylinder 510 erodesduring operation of the sputtering apparatus, the motorized actuationmechanisms adjust the position of magnet bar structure 425 with respectto inner surface 511 in response to control signals from the electroniccontroller in controller and battery module 418.

As illustrated in FIG. 15, end cap 514 houses a window 540 that allowsan optical signal to be transmitted between a first fiber optic cable542 and a second fiber optic cable 544. The fiber optic support 520 ispositioned such that a small gap 546 exists between facing surfaces offiber optic support 520 and end cap 514, where the optical signal istransmitted between fiber optic cables 542 and 544. The first fiberoptic cable 542 extends into fiber optic holder 437, coupled to end cap514, from magnetron assembly 400. The second fiber optic cable 544extends into an opening 548 of fiber optic support 520.

In one embodiment, fiber optic cable 544 is in optical communicationwith an optical transceiver located outside of a vacuum chamber in whichtarget cathode 500 is implemented. The fiber optic cable 542 isoptically coupled to an optical transceiver in communication with theelectronic controller in controller and battery module 418. The tips offiber optic cables 542 and 544, on either side of window 540, are insufficient alignment such that optical signals can be effectivelytransmitted between fiber optic cables 542 and 544.

FIGS. 16 and 17 illustrate a rotary target cathode 600 that isimplemented with magnetron assembly 400 according to another embodiment.The cathode 600 includes a rotatable target cylinder 610 that isconfigured at a proximal end 612 for mounting to an end block. A targetend cap 614 is affixed to a distal end 616 of target cylinder 610.

A target end support 618, configured to be mounted to a vacuum chamberwall of a sputtering apparatus, is coupled to end cap 614. A fiber opticsupport 620, configured to be mounted to the vacuum chamber wall, ispositioned such that fiber optic support 620 is adjacent to but spacedapart from end cap 614. The end cap 614 and fiber optic support 620 aredescribed in further detail with reference to FIG. 18 hereafter.

FIG. 17 shows further details of magnetron assembly 400, which includethe same components as shown in FIG. 14. As such, drive modules 410 eachinclude a motor 530 coupled to an actuation mechanism 534. A set ofactuation posts 538 is coupled between magnet bar structure 425 and eachactuation mechanism 534. The motorized actuation mechanisms 534 providefor adjustments in the position of magnet bar structure 425 relative tothe inner surface of target cylinder 610.

As illustrated in FIG. 18, end cap 614 houses a window 640 that allowsan optical signal to be transmitted between a first fiber optic cable642 and a second fiber optic cable 644. The fiber optic support 620 ispositioned such that a small gap 646 exists between facing surfaces offiber optic support 620 and end cap 614, where the optical signal istransmitted between fiber optic cables 642 and 644. The first fiberoptic cable 642 extends into fiber optic holder 437, coupled to end cap614, from magnetron assembly 400. The second fiber optic cable 644extends into an opening 648 of fiber optic support 620.

In one embodiment, fiber optic cable 644 is in optical communicationwith an optical transceiver located outside of a vacuum chamber in whichtarget cathode 600 is implemented. The fiber optic cable 642 isoptically coupled to an optical transceiver in communication with theelectronic controller in controller and battery module 418. The tips offiber optic cables 642 and 644, on either side of window 640, are insufficient alignment such that optical signals can be effectivelytransmitted between fiber optic cables 642 and 644.

EXAMPLE EMBODIMENTS

Example 1 includes a magnetron assembly for a rotary target cathode, themagnetron assembly comprising: an elongated support structure; a magnetbar structure movably positioned below the support structure; aplurality of drive modules coupled to the support structure, the drivemodules each including a motorized actuation mechanism operativelycoupled to the magnet bar structure; a controller and battery modulecoupled to the support structure and in operative communication with thedrive modules, the controller and battery module including an electroniccontroller and at least one rechargeable battery, the battery configuredto energize each motorized actuation mechanism and the electroniccontroller; and one or more power generation modules coupled to thesupport structure and in electrical communication with the battery suchthat electrical energy output from the power generation modulesrecharges the battery.

Example 2 includes the magnetron assembly of Example 1, wherein the oneor more power generation modules are configured to directly drive themotorized actuation mechanism in each of the drive modules.

Example 3 includes the magnetron assembly of any of Examples 1-2,further comprising at least one cooling pipe that extends along thesupport structure.

Example 4 includes the magnetron assembly of Example 3, wherein the oneor more power generation modules are in fluid communication with thecooling pipe.

Example 5 includes the magnetron assembly of Example 4, whereinmechanical energy for driving the one or more power generation modulesis harnessed from water that flows through the cooling pipe.

Example 6 includes the magnetron assembly of Example 5, wherein the oneor more power generation modules include a turbine generator in fluidcommunication with the water that flows through the cooling pipe.

Example 7 includes the magnetron assembly of any of Examples 1-6,wherein the magnet bar structure includes an array of magnets thatextends along and under the support structure.

Example 8 includes the magnetron assembly of any of Examples 1-7,further comprising a fiber optic cable optically coupled to an opticaltransceiver in communication with the electronic controller.

Example 9 includes the magnetron assembly of Example 8, furthercomprising a fiber optic holder that extends from one end of themagnetron assembly and supports an end section of the fiber optic cable.

Example 10 includes a rotary target cathode assembly for a sputteringapparatus, the rotary target cathode assembly comprising: a rotatabletarget cylinder having an inner surface that defines an interiorpassageway, the target cylinder configured at a proximal end formounting to an end block of the sputtering apparatus; a target end capaffixed to a distal end of the target cylinder; and a magnetron assemblydisposed in the interior passageway of the target cylinder. Themagnetron assembly comprises: an elongated support structure; a magnetbar structure movably positioned below the support structure; aplurality of drive modules coupled to the support structure, the drivemodules each including a motorized actuation mechanism operativelycoupled to the magnet bar structure; a controller and battery modulecoupled to the support structure and in operative communication with thedrive modules, the controller and battery module including an electroniccontroller and at least one rechargeable battery, the battery configuredto energize each motorized actuation mechanism and the electroniccontroller; and one or more power generation modules coupled to thesupport structure and in electrical communication with the battery suchthat electrical energy output from the power generation modulesrecharges the battery. As the target cylinder erodes during operation ofthe sputtering apparatus, the motorized actuation mechanisms adjust theposition of the magnet bar structure with respect to the inner surfaceof the target cylinder in response to control signals from theelectronic controller.

Example 11 includes the rotary target cathode assembly of Example 10,further comprising a fiber optic support configured to be mounted to avacuum chamber wall of the sputtering apparatus such that the fiberoptic support is adjacent to and spaced apart from the target end cap.

Example 12 includes the rotary target cathode assembly of any ofExamples 10-11, and further comprising a first fiber optic cableoptically coupled to a first optical transceiver in communication withthe electronic controller, the first fiber optic cable extending intothe target end cap from the magnetron assembly.

Example 13 includes the rotary target cathode assembly of Example 12,and further comprising a second fiber optic cable optically coupled to asecond optical transceiver located outside of the vacuum chamber wall,the second fiber optic cable extending into an opening in the fiberoptic support.

Example 14 includes the rotary target cathode assembly of Example 13,wherein the target end cap includes a window that allows an opticalsignal to be transmitted between the first fiber optic cable and thesecond fiber optic cable.

Example 15 includes the rotary target cathode assembly of any ofExamples 10-14, wherein the one or more power generation modules isconfigured to directly drive the motorized actuation mechanism in eachof the drive modules.

Example 16 includes the rotary target cathode assembly of any ofExamples 10-15, and further comprising at least one cooling pipe thatextends along the support structure of the magnetron assembly.

Example 17 includes the rotary target cathode assembly of Example 16,wherein the one or more power generation modules are in fluidcommunication with the cooling pipe.

Example 18 includes the rotary target cathode assembly of Example 17,wherein mechanical energy for driving the one or more power generationmodules is harnessed from water that flows through the cooling pipe.

Example 19 includes the rotary target cathode assembly of Example 18,wherein the one or more power generation modules include a turbinegenerator in fluid communication with the water that flows through thecooling pipe.

Example 20 includes the rotary target cathode assembly of any ofExamples 10-16, wherein mechanical energy for driving the one or morepower generation modules is harnessed from rotational energy of thetarget cylinder.

While a number of embodiments have been described, it will be understoodthat the described embodiments are to be considered only as illustrativeand not restrictive, and that various modifications to the describedembodiments may be made without departing from the scope of theinvention. The scope of the invention is therefore indicated by theappended claims rather than by the foregoing description. All changesthat come within the meaning and range of equivalency of the claims areto be embraced within their scope.

What is claimed is:
 1. A magnetron assembly for a rotary target cathode,the magnetron assembly comprising: an elongated support structure; amagnet bar structure movably positioned below the support structure; aplurality of drive modules coupled to the support structure, the drivemodules each including a motorized actuation mechanism operativelycoupled to the magnet bar structure; a controller and battery modulecoupled to the support structure and in operative communication with thedrive modules, the controller and battery module including an electroniccontroller and at least one rechargeable battery, the battery configuredto energize each motorized actuation mechanism and the electroniccontroller; and one or more power generation modules coupled to thesupport structure and in electrical communication with the battery suchthat electrical energy output from the one or more power generationmodules recharges the battery.
 2. The magnetron assembly of claim 1,wherein the one or more power generation modules is configured todirectly drive the motorized actuation mechanism in each of the drivemodules.
 3. The magnetron assembly of claim 1, further comprising atleast one cooling pipe that extends along the support structure.
 4. Themagnetron assembly of claim 3, wherein the one or more power generationmodules are in fluid communication with the cooling pipe.
 5. Themagnetron assembly of claim 4, wherein mechanical energy for driving theone or more power generation modules is harnessed from water that flowsthrough the cooling pipe.
 6. The magnetron assembly of claim 5, whereinthe one or more power generation modules include a turbine generator influid communication with the water that flows through the cooling pipe.7. The magnetron assembly of claim 1, wherein the magnet bar structureincludes an array of magnets that extends along and under the supportstructure.
 8. The magnetron assembly of claim 1, further comprising afiber optic cable optically coupled to an optical transceiver incommunication with the electronic controller.
 9. The magnetron assemblyof claim 8, further comprising a fiber optic holder that extends fromone end of the magnetron assembly and supports an end section of thefiber optic cable.
 10. A rotary target cathode assembly for a sputteringapparatus, the rotary target cathode assembly comprising: a rotatabletarget cylinder having an inner surface that defines an interiorpassageway, the target cylinder configured at a proximal end formounting to an end block of the sputtering apparatus; a target end capaffixed to a distal end of the target cylinder; a magnetron assemblydisposed in the interior passageway of the target cylinder, themagnetron assembly comprising: an elongated support structure; a magnetbar structure movably positioned below the support structure; aplurality of drive modules coupled to the support structure, the drivemodules each including a motorized actuation mechanism operativelycoupled to the magnet bar structure; a controller and battery modulecoupled to the support structure and in operative communication with thedrive modules, the controller and battery module including an electroniccontroller and at least one rechargeable battery, the battery configuredto energize each motorized actuation mechanism and the electroniccontroller; and one or more power generation modules coupled to thesupport structure and in electrical communication with the battery suchthat electrical energy output from the one or more power generationmodules recharges the battery; wherein as the target cylinder erodesduring operation of the sputtering apparatus, the motorized actuationmechanisms adjust the position of the magnet bar structure with respectto the inner surface of the target cylinder in response to controlsignals from the electronic controller.
 11. The rotary target cathodeassembly of claim 10, further comprising a fiber optic supportconfigured to be mounted to a vacuum chamber wall of the sputteringapparatus such that the fiber optic support is adjacent to and spacedapart from the target end cap.
 12. The rotary target cathode assembly ofclaim 11, further comprising a first fiber optic cable optically coupledto a first optical transceiver in communication with the electroniccontroller, the first fiber optic cable extending into the target endcap from the magnetron assembly.
 13. The rotary target cathode assemblyof claim 12, further comprising a second fiber optic cable opticallycoupled to a second optical transceiver located outside of the vacuumchamber wall, the second fiber optic cable extending into an opening inthe fiber optic support.
 14. The rotary target cathode assembly of claim13, wherein the target end cap includes a window that allows an opticalsignal to be transmitted between the first fiber optic cable and thesecond fiber optic cable.
 15. The rotary target cathode assembly ofclaim 10, wherein the one or more power generation modules is configuredto directly drive the motorized actuation mechanism in each of the drivemodules.
 16. The rotary target cathode assembly of claim 10, furthercomprising at least one cooling pipe that extends along the supportstructure of the magnetron assembly.
 17. The rotary target cathodeassembly of claim 16, wherein the one or more power generation modulesare in fluid communication with the cooling pipe.
 18. The rotary targetcathode assembly of claim 17, wherein mechanical energy for driving theone or more power generation modules is harnessed from water that flowsthrough the cooling pipe.
 19. The rotary target cathode assembly ofclaim 18, wherein the one or more power generation modules include aturbine generator in fluid communication with the water that flowsthrough the cooling pipe.
 20. The rotary target cathode assembly ofclaim 10, wherein mechanical energy for driving the one or more powergeneration modules is harnessed from rotational energy of the targetcylinder.